Infrascope

The Infrascope™ is a novel non-invasive cardiovascular diagnostic device designed to extend cardiac auscultation into previously inaccessible frequency domains. Unlike traditional stethoscopes, phonocardiographs, ECG, or echocardiography, the Infrascope captures the full spectrum of low-frequency mechanical vibrations generated by the heart and vascular system, including components that fall below the human auditory threshold. By converting these sub-audible signals into an audible and temporally expanded form, the Infrascope provides clinicians with new diagnostic information on cardiac mechanics, valve timing, and vascular flow dynamics.

Operating Principle

The human cardiovascular system produces a rich spectrum of mechanical activity with a fundamental frequency corresponding to the cardiac cycle, typically near 1 Hz. Physiologically important mechanical events - valve closures, ventricular wall motion, and arterial flow turbulence - generate vibrational energies concentrated largely within the 1-20 Hz band. These frequencies lie below the lower limit of human hearing and therefore cannot be perceived directly, even when amplified by conventional or digital stethoscopes.

The Infrascope circumvents this limitation by performing frequency transposition: it acquires mechanical vibrations from approximately 1-150 Hz and shifts them into the 20-1000 Hz audible range without distorting their temporal or relative amplitude relationships. As a result, clinicians can perceive mechanical events that were previously undetectable.

Enhanced Valve Timing Assessment

One direct advantage of low-frequency transposition is the ability to resolve fine temporal features of valve function. For example, in most individuals, the first heart sound (S1) reflects the near-simultaneous closure of the mitral and tricuspid valves. The tricuspid component typically lies predominantly in the infrasonic band ( <20 Hz), rendering it inaudible through standard auscultation. When monitored with the Infrascope, S1 is frequently perceived as two distinct sequential events, enabling precise assessment of mitral-tricuspid closure timing. Such measurements may support the evaluation of conduction abnormalities, right and left heart mechanical synchrony, and subtle valvular pathology.

Temporal Stretching Mode

The Infrascope also provides a signal "stretching" mode, in which the recorded cardiac cycle is temporally expanded while maintaining proportional timing between events. This expansion allows the human auditory system to resolve extremely brief acoustic signatures - such as early systolic murmurs, turbulent jets, or transient vibration bursts - that typically fall below perceptual limits due to their short duration. In stretch mode, systolic flow disturbances that are otherwise imperceptible become clearly audible and analyzable.

Vascular Turbulence and Atherosclerotic Assessment

Beyond cardiac sounds, the Infrascope captures low-frequency arterial turbulence generated in both central and peripheral vessels. These signals provide a new class of diagnostic information related to vessel compliance, flow irregularities, and early atherosclerotic changes. Because traditional auscultation is largely insensitive to such low-frequency phenomena, the Infrascope offers a unique opportunity to assess vascular health through mechanical signatures that were previously inaccessible.

Summary

By expanding cardiac and vascular acoustics into the sub-audible domain and presenting them in an interpretable audible form, the Infrascope represents a significant advancement in non-invasive cardiovascular diagnostics. It enables detailed assessment of valve timing, detection of subtle murmurs, and characterization of vascular turbulence-capabilities not achievable with existing stethoscopes or standard acoustic devices. As such, the Infrascope has the potential to enhance, complement, and in some applications transform traditional cardiovascular examination methods.